GL_APPLE_shader_framebuffer_fetch gl_lastFragData

问题

Apple introduced a new shader extension called GL_APPLE_shader_framebuffer_fetch, which allows fully programmable blending. There is also a wwdc video explaining the functionallity. It's the video 513 of wwdc 2012.

Sadly this extension doesn’t work for me.

F-Shader:

#extension GL_APPLE_shader_framebuffer_fetch : require

varying lowp vec4 colorVarying;

void main(void) {
    gl_FragColor = gl_lastFragData[0] + vec4(colorVarying.x, colorVarying.y, colorVarying.z, 1.0);
}

Debug output: extension ‘GL_APPLE_shader_framebuffer_fetch’ is not supported

Tried to run it on the iOS 6.0 iPad Simulator ‘n on an actual iPad with 6.0

How can that be? What do I have to do to actually use this extension?

回答1:

Try GL_EXT_shader_framebuffer_fetch it was called GL_APPLE_shader_framebuffer_fetch in the Beta, but it got renamed in the final release (according to the iOS6 release notes).

来源：https://stackoverflow.com/questions/13974218/gl-apple-shader-framebuffer-fetch-gl-lastfragdata